A plasma device serves as an antenna, single or stacked plasma frequency
selective surfaces, single or stacked plasma antenna arrays, plasma
lamps, plasma limiters, plasma switch, plasma windows or plasma phase
shifters. An electromagnetic wave signal is controlled to have a plasma
frequency matched as nearly as possible to the frequency of incident
electromagnetic signals for maximizing the antenna aperture and
efficiency. Matching the frequencies permits the plasma device to have a
physical size and shape substantially independent of the conventional
optimal size and shape for a given transceived signal frequency. The
plasma device plasma frequency is adjustable for tuning to different
incident signal frequencies, thereby providing flexibility not available
from conventional metal antennas.